Longer duration of untreated psychosis (DUP) is linked to poorer outcomes in first-episode psychosis (FEP). Coordinated Specialty Care (CSC), exemplified by New York State?s OnTrackNY programs, improves outcomes through early, multi-component care; however, DUP remains unacceptably long. There is evidence that young adults with FEP who are involved in the criminal justice (CJ) system (where there is likely a much greater prevalence of undetected, untreated psychosis than in the general population) have an alarmingly long DUP. Thus, although primary care settings (e.g., clinics) and educational institutions (e.g., colleges) may be important sites for early detection, there is a need to establish early detection services within the CJ system (and in particular, urban jails) and to create pathways from CJ involvement to CSC enrollment. Relying on prior research, relevant theory, and our findings on DUP, pathways to care, CSC, and the CJ system, we propose 4 intervention development aims. First, we will implement a ?Public Information Campaign? (PIC) in 2 jails at New York City?s Rikers Island, which will detect FEP earlier, reduce our DUP-1 (psychosis onset to medication initiation) and lead to referrals of detainees to the Early Detection Team (EDT). The PIC will accomplish this via three measurable targets/mediators (cumulative number of print materials disseminated in the jail, cumulative number of Corrections Officers and Correctional Health Services staff trained in early psychosis and how to refer to EDT, and change in scores on 3 Social Cognitive Theory constructs [Study 1]). Second, we will implement an EDT in the same 2 jails, which will increase the likelihood of referred detainees found to have FEP engaging with CSC (e.g., an OnTrackNY program in the detainee?s borough of residence) upon release, and reduce our DUP-2 (psychosis onset to CSC enrollment). The EDT will accomplish these goals via a key target/mediator (minutes of face-to-face contact with the detainee while in jail and telephone contact following release). Clinical interviews with detainees referred to the EDT will comprise Study 2. Third, we will thoroughly study acceptability and feasibility of the jail-based PIC and EDT, which will give us information needed in advance of a larger, multi-site, definitive effectiveness trial. Regarding acceptability, we will conduct stakeholder interviews and focus groups with all relevant end-users of the new intervention (PIC+EDT) [Study 3]. In terms of feasibility for a larger trial, data on a number of metrics will be collected. Fourth, we will prepare an Intervention Manual for broader use in diverse jails and further formal research. In summary, city and county jails likely have a relatively high number of young people with undetected and untreated FEP, stemming from the criminalization of mental illnesses, fragmentation between CJ and mental health sectors, and a lack of early detection initiatives in such settings to date. Once the PIC and EDT are successfully implemented in this ideal site for pilot testing, and once acceptability and feasibility are established, DUP may be reduced, and engagement with CSC enhanced, for this especially vulnerable group.